If holes are drilled through a concrete slab and through a damp-proof membrane under the concrete slab and grout is pumped into it, how do they fix the fact they have now punctured the damp-proof membrane under the concrete slab, risking moisture seeping into the house?
Asked: 4 June 2015
Ministry of Business, Innovation, and Employment advises:
Provided the limits in this guidance are met the performance of the vapour barrier remains adequate, as any moisture from vapour through the membrane holes provides no change to the condition in the house. The membrane is not intended to be a free water barrier.
For more about this type of issue, please see http://www.building.govt.nz/guidance-on-repairs-after-quake-issue-08#aid56